Embodiments of the present invention relate to an array substrate, a liquid crystal display (LCD) device comprising the same, and a method for manufacturing the same.
In the market of flat panel displays, liquid crystal display (LCD) devices have obtained a relatively dominant position because of the characteristics such as smaller volume, lighter weight, lower power consumption, lower radiation, and etc. Generally, a LCD device comprises a backlight for emitting light and a liquid crystal panel comprising a thin film transistor (TFT) array substrate and an opposing color filter substrate with a liquid crystal (LC) layer interposed therebetween. Gate lines for transmitting scan signals, data lines for transmitting data signals, and pixel electrodes for respective pixels are formed on the array substrate. The LCD device can display a desired image by applying an electric field to the LC layer and controlling the intensity of the electric field, thereby adjusting the amount of light that is transmitted through the substrates.
To add a touch screen function to a LCD device, an additional touch panel is typically attached onto the front of the liquid crystal panel of the LCD device. The touch panel can read information corresponding to user's input position when touched.
However, the LCD device having a touch panel attached thereon may have following disadvantages: (1) overall thickness of the display device is increased by the attached touch panel, and additional processes are required for attaching the touch panel, making the manufacture process complicated, and leading to an increase of cost; (2) the touch panel decreases transmissivity of the light transmitted through the liquid crystal panel and causes light parallax, which makes the reproduced image excessively floating and deteriorates the image quality; and (3) lifetime of the touch panel can be shorten because the panel is exposed outside and suffers from external influence.
The Chinese patent application 200480032685.2 provided a LCD device having a touch screen function, in which a first switching element, a second switching element and a third switching element are formed in each of the pixel regions defined by gate lines and data lines on the array substrate in a matrix form. The second and third switching elements are designed to detect variation in liquid crystal capacitance caused by touch. The method for manufacturing this conventional LCD device also has been provided. The conventional LCD device requires two additional switching elements in each pixel region, and therefore its structure become complicated and the number of manufacture processes increases. Further, the aperture ratio is decreased.